what is a good upgrade to replace a stock yj power brake booster. allready have merc m/c f/r disc d44 and adjustable prop valve. still need alittle more power. any help please.

How about stronger legs? :flipoff2:

i replaced mine with a booster from a gm 1 ton truck when i did my axle swap.it just bolted up.you may have to replace the pin that engages the brakes mine had to be lenghtened,we used a threaded bolt and cut the head off of it and smoothed it out.sorry for my terminology im not sure of the exact term for that pin.i also used some heavy duty black sealant just to prevent any leaks where the booster meets the mc.its working very well

more power = hydroboost. http://www.vancopbs.com/ has a bolt in kit for the YJ. I love my kit from Vanco, it made a huge difference in stopping power on my rig.

I have booster and master out of grand marquie and running dana 44 and 9" both disc. My setup feels similar if not the same as my friend's vanco setup good luck.

i replaced mine with a booster from a gm 1 ton truck when i did my axle swap.it just bolted up.---

Mind elaborating? Specific model of truck, or part number?
Did you use the truck's MC?

I assume you did this on an XJ (your signature)? If so, any problems with clearances? Do you have a clutch MC that sets next to the booster? If so, any clearance issues?